Essay questions are generally used to assess complex, college-level coursework, particularly at the graduate school level. To demonstrate understanding of complex course material in response to an essay question, a student is generally expected to write a long answer, in a natural language grammar syntax, that conveys thoughts, real-world examples and defines complex solutions to test cases or scenarios. Essay questions are a superior method of evaluating a person's understanding of a course with multiple complex topics, relative to multiple choice and fill-in-the-blank testing techniques.
Essay examinations provide means for establishing whether students have mastered essential concepts within coursework. In drafting an answer to an essay question a student is generally expected to demonstrate understanding of complicated topics in essay form. However, long answer, essay-type questions do not generally have a single correct answer. As such, individual answers to the same question can vary greatly, while still satisfying the requirements of said question.
A correct, or relatively better answer, expresses an understanding of the essential concepts of a coursework corpus knowledge within the response text, rather than simply providing an expected answer. It is difficult to define a uniform and consistent, objective grading scheme for essay questions, one that is not impacted by divergent student performances with respect to individualized grammar usage and structures, or spelling errata. Graders must define standards for point deductions or increases that are reliably replicable and consistent across a wide variety of student performances. When teams of graders, or different assessment devices, are used to correct an exam, grades tend to vary for given answer over different graders or assessment devices.